Numerous electrical power generating systems exist for generating AC and DC electrical power. It is a design objective of electrical power generating systems to achieve the highest possible energy conversion efficiency. In an AC generating system, the intent is to eliminate undesired harmonics. In a DC power generating system, the intent is to eliminate ripple. The prior art utilizes numerous mechanisms for attenuating undesired AC components which are produced by AC and DC power generating systems using passive or active filtering techniques. These systems are effective in eliminating the undesirable and potentially load damaging AC frequencies. However, filtering inherently results in a lowering of energy conversion efficiency as a consequence of the undesired AC components being eliminated from the energy which is applied to the load by filtering. Moreover, the filters which are required to eliminate the undesired AC components in high power electrical power generating systems are heavy in weight which is a disadvantage for applications such as in airframes where elimination of weight is of extreme importance. Additionally, filters for high power applications are expensive and are sizable which is an additional disadvantage in applications such as airframes where space allocation is important.
Examples of power generating systems which are designed to lessen harmonics are disclosed in U.S. Pat. Nos. 3,241,038, 3,501,686, 3,839,667, 4,204,264 and 4,382,275.
In state of the art electrical power generating systems substantial energy is lost in the power generating process as undesired harmonics or ripple. A typical AC generating system, such as the type utilized in an airframe prior to filtering of the output AC, has from 3%-8% of its total output power contained in undesired harmonics. Reduction of the harmonic content outputted by an AC generating system and ripple in a DC power generating system in an airframe is highly desirable from an operating standpoint. Achieving of a higher power generation efficiency than currently available to date would permit the rated capacity of the power generating systems to be downsized resulting in an attendant weight savings and further would potentially result in a reduction in weight of the required filtering depending upon the weight of additional components required to electronically lower harmonic or ripple content.